Aging elicits quantitative and qualitative changes in different immune components, leading to disruption of tolerogenic circuits and development of autoimmune disorders. Galectin-1 (Gal1), an endogenous glycan-binding protein, has emerged as a regulator of immune cell homeostasis by shaping the fate of myeloid and lymphoid cells. Here, we demonstrate that aged Gal1-null mutant (Lgals1^−/−) mice develop a spontaneous inflammatory process in salivary glands that resembles Sjögren’s syndrome. This spontaneous autoimmune phenotype was recapitulated in mice lacking β1,6N-acetylglucosaminyltransferase V (Mgat5), an enzyme responsible for generating β1,6-branched complex N-glycans, which serve as a major ligand for this lectin. Lack of Gal1 resulted in CD11c⁺ dendritic cells (DCs) with higher immunogenic potential, lower frequency of Foxp3⁺ regulatory T cells (Tregs), and increased number of CD8⁺ T cells with greater effector capacity. Supporting its tolerogenic activity, Gal1 expression decreased with age in autoimmunity-prone nonobese diabetic (NOD) mice. Treatment with recombinant Gal1 restored tolerogenic mechanisms and reduced salivary gland inflammation. Accordingly, labial biopsies from primary Sjögren’s syndrome patients showed reduced Gal1 expression concomitant with higher number of infiltrating CD8⁺ T cells. Thus, endogenous Gal1 serves as a homeostatic rheostat that safeguards immune tolerance and prevents age-dependent development of spontaneous autoimmunity. Significance Different immune inhibitory circuits act in concert to prevent and limit the extent of deleterious autoimmune reactions occurring during the aging process. An in-depth understanding of these pathways is critical for implementation of more selective and powerful immunomodulatory modalities capable of attenuating autoimmune inflammation. Here we show that lack of galectin-1 (an endogenous β-galactoside-binding protein) or specific N-glycosylated ligands leads to a gradual breakdown of tolerogenic programs and to the establishment of age-related salivary gland autoimmunity. This study emphasizes the role of lectin–glycan interactions in the maintenance and restoration of immune tolerance and highlights their clinical relevance and therapeutic potential in chronic inflammatory disorders.

Diverse immunoregulatory circuits operate to preserve intestinal homeostasis and prevent inflammation. Galectin-1 (Gal1), a β-galactoside–binding protein, promotes homeostasis by reprogramming innate and adaptive immunity. Here, we identify a glycosylation-dependent “on-off” circuit driven by Gal1 and its glycosylated ligands that controls intestinal immunopathology by targeting activated CD8⁺ T cells and shaping the cytokine profile. In patients with inflammatory bowel disease (IBD), augmented Gal1 was associated with dysregulated expression of core 2 β6-N-acetylglucosaminyltransferase 1 (C2GNT1) and α(2,6)-sialyltransferase 1 (ST6GAL1), glycosyltransferases responsible for creating or masking Gal1 ligands. Mice lacking Gal1 exhibited exacerbated colitis and augmented mucosal CD8⁺ T cell activation in response to 2,4,6-trinitrobenzenesulfonic acid; this phenotype was partially ameliorated by treatment with recombinant Gal1. While C2gnt1^−/− mice exhibited aggravated colitis, St6gal1^−/− mice showed attenuated inflammation. These effects were associated with intrinsic T cell glycosylation. Thus, Gal1 and its glycosylated ligands act to preserve intestinal homeostasis by recalibrating T cell immunity.

Galectins (Gals), a family of multifunctional glycan-binding proteins, have been traditionally defined as (3-galactoside binding lectins. However, certain members of this family have shown selective affinity toward specific glycan structures including human milk oligosaccharides (HMOs) and blood group antigens. In this work, we explored the affinity of human galectins (particularly Gal-1, -3, -4, -7, and -12) toward a panel of oligosaccharides including HMOs and blood group antigens using a complementary approach based on both experimental and computational techniques. While prototype Gal-1 and Gal-7 exhibited differential affinity for type I versus type II Lac/LacNAc residues and recognized fucosylated neutral glycans, chimera-type Gal-3 showed high binding affinity toward poly-LacNAc structures including LNnH and LNnO. Notably, the tandem-repeat human Gal-12 showed preferential recognition of 3-fucosylated glycans, a unique feature among members of the galectin family. Finally, Gal-4 presented a distinctive glycan-binding activity characterized by preferential recognition of specific blood group antigens, also validated by saturation transfer difference nuclear magnetic resonance experiments. Particularly, we identified oligosaccharide blood group A antigen tetraose 6 (BGA6) as a biologically relevant Gal-4 ligand, which specifically inhibited interleukin-6 secretion induced by this lectin on human peripheral blood mononuclear cells. These findings highlight unique determinants underlying specific recognition of HMOs and blood group antigens by human galectins, emphasizing the biological relevance of Gal-4-BGA6 interactions, with critical implications in the development and regulation of inflammatory responses.

Cancer is a global disease, yet a paradox persists: The most advanced research ecosystems are concentrated in countries with lower disease burden, whereas low- and middle-income countries (LMIC)—carrying 70% of the global cancer burden—face major constraints in research capacity. Closing this gap is essential for equitable progress in cancer prevention, diagnosis, and treatment. Researchers in LMICs are creatively adapting established technologies, research pipelines, and collaborative models from higher-resource settings to local solutions. In this study, 25 American Association for Cancer Research Global Scholar-in-Training Award recipients from LMICs share how cancer research is advancing within resource-limited settings, focused on (i) infrastructure and resources, (ii) training and talent retention, (iii) funding and sustainability, and (iv) cultural and social barriers. We identified shared challenges and cross-cutting solutions, discussed gaps, and suggested steps to further advancing cancer research. We emphasized locally led innovation, strategic partnerships, and community engagement. These perspectives offer a framework for inclusive, synergistic approaches to strengthening cancer research and accelerating impact where it is needed most.

Background: In spite of compelling evidence demonstrating safety and immunogenicity of adenoviral-based SARS-CoV-2 vaccines in the general population, its effects in socially vulnerable elderly individuals are poorly understood. Here we aimed to investigate the efficacy of two doses of combined vector vaccine, the Gam-COVID-Vac (Sputnik-V vaccine), at 14, 42, and 180 days after immunization, in a nursing home for underprivileged population and homeless individuals. Methods: A phase 3, open-label clinical trial involving administration of two adenoviral vectors (Ad26-Ad5) vaccine, in elderly individuals over the ages of 60 years was performed. SARS-CoV-2 Spike RBD-specific IgG antibodies at days 21-, 42- and 180 post-vaccination was analyzed in sera of individuals receiving two doses of the Sputnik-V vaccine with an interval of 21 days. SARS-CoV-2-specific CD8+ T cell responses, measured by intracellular tumor necrosis factor (TNF) was determined by flow cytometry following antigen-specific cultures. Results: A total of 72 elderly adults with a mean age of 72.6 ± 9.5 years-old was selected after applying the inclusion criteria, all corresponding to an underprivileged population. Two-doses vaccination with Sputnik-V vaccine elicited an antibody-mediated immune response (revealed by quantitative detection of SARS-CoV-2-specific IgG antibodies, CMIA) 70% at day 21, 90% at day 42, and 66.1% at day 180. Fully vaccinated individuals had robust SARS-CoV-2-specific T cell responses, evidenced by TNF production in CD4+ and CD8+ T cells in all time periods analyzed. Conclusion: Six months after receipt of the second dose of the Gam-COVID-Vac vaccine, SARS-CoV-2-specific IgG levels declined substantially among the tested population, whereas CD4+ and CD8+ T-cell-mediated immunity remained at high levels. These data suggest that two doses of combined adenoviral-based vaccine elicits a considerable level of SARS-CoV-2 immune responses in elderly individuals, highlighting its safety and immunogenicity in this highly vulnerable population.

A healthy gut immune system balances pathogen defense and tolerance to beneficial microbes. This equilibrium is sustained by coordinated mechanisms where B cells (BCs) play a central role, and secretory immunoglobulin A (SIgA) regulates microbiome composition. In ulcerative colitis (UC), impaired tolerogenic pathways result in exaggerated immune activation, epithelial dysfunction, and tissue damage; however, the contribution of BCs to disease pathogenesis remains unclear. Notably, sialylation is crucial to B-cell function, but its relevance in the intestinal IgA B-cell response has been scarcely explored. Here, we show that SIgA from active UC patients displays an inflammation-dependent reduction in α(2,6)-sialylation. This desiaylation is recapitulated in dextran sodium sulfate-induced colitis, where IgA+ plasma cells (IgA+ PCs) and BCs exhibit a similar glycophenotype. Functional analyses reveal that BCs lacking α(2,6)-sialylation on N-glycans exhibit defective differentiation into IgA+ PCs and diminished capacity to suppress intestinal inflammation in vivo, with increased neutrophil infiltration. Moreover, transcriptomic analyses of UC patient samples suggest a synergistic contribution of neuraminidase activity and reduced bioavailability of sialic acid precursors, leading to SIgA desialylation. Collectively, these findings uncover a glycosylation-dependent pathological circuit in which altered sialylation of SIgA and BCs disrupts their function, compromising mucosal homeostasis in intestinal inflammation.